No idea, but I still remember as a Junior in the ROC back in 1980 getting covered with well fermented rice pudding which exploded from the tin as I opened it. I'm so glad no one had a camera with them during that late night exercise. Caused much mirth at the time (at my expense).

Of course these days I would have been charged under the Terrorism Act for discharging an explosive device in an enclosed chamber: the ROC Post!